Educational Resources

Scan Head

A scan head consists of two mirrors, each mounted on very small rotary motors, called galvanometers or “galvos ” for short. These two mirrors and motors are mounted orthogonally to each other such that the rotary motion of the two mirrors translates to linear motion in the X- and Y-axis. The small size of the motors provides high-speed positioning, short settling times, and high acceleration and deceleration, which is ideal for high-speed, short-distance motion.

Figure 1 is a schematic of the laser and scan head more commonly known as a galvo laser. The laser is moved by high speed low inertia galvanometer motors mounted with mirrors through a lens produces a focal XY plane for welding. Also shown is the scan head, the laser delivered to the beam expander/collimator. The size of the assembly is about 20-inches x 6-inches x 6-inches.

In addition to the mirrors an “F-theta lens” focuses the laser over an X/Y area according to where the motors have positioned the laser at the input side of the lens. This contrasts with a regular lens, which focuses to a single point in X and Y. Many laser processes use the galvo laser concept such as laser marking, laser welding, femtosecond laser micromachining to name a few.​Read more in our blog piece "Scan heads for micro laser welding: “Ham n’ Eggs” of laser industry"